CN1268882C - Air conditioner and its control method - Google Patents
Air conditioner and its control method Download PDFInfo
- Publication number
- CN1268882C CN1268882C CN 200310103272 CN200310103272A CN1268882C CN 1268882 C CN1268882 C CN 1268882C CN 200310103272 CN200310103272 CN 200310103272 CN 200310103272 A CN200310103272 A CN 200310103272A CN 1268882 C CN1268882 C CN 1268882C
- Authority
- CN
- China
- Prior art keywords
- mentioned
- evaporimeter
- expansion valve
- temperature
- air conditioner
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Air Conditioning Control Device (AREA)
Abstract
A temperature sensor of a heat exchanger functioning as an evaporator is attached to an intermediate part of the heat exchanger so that effect of expansion valve opening is small and an average temperature of the heat exchanger can be detected. By using its output and a rotational frequency of a compressor 1, optimum restrictor opening maximizing evaporator heat exchange efficiency is calculated by a calculation block 71 by an arithmetic equation determined beforehand by experiments to control an electronic expansion valve 5.
Description
Technical field
The present invention relates to constitute the aperture control technology of electric expansion valve of the freeze cycle of frequency conversion type air conditioning machine, especially relate to the air conditioner and the control method thereof of not carrying out FEEDBACK CONTROL and carrying out the aperture control of suitable expansion valve.
Background technology
Usually, air conditioner has as shown in Figure 8 by compressor 1, cross valve (hereinafter referred to as valve) 2, indoor heat converter (below, be called heat exchanger) 3, outdoor heat converter (below, be called heat exchanger) 4, expansion valve (below, be called valve) 5 freeze cycle of forming.
When cooling operation, this air conditioner control valve 2 flows and Returning heat-exchanger 3 refrigerant from the order of heat exchanger 3 by compressor 1, heat exchanger 4, valve 5 shown in dotted arrow.Like this, heat exchanger 3 is as the heat around evaporimeter performance function and the absorption.On the other hand, this air conditioner makes its rotation according to the fan (not shown) of a side in the control rooms such as setting air quantity of remote controller, thereby will be blown out to indoor through the cold wind that heat exchanger 3 has carried out heat exchange.And, to make compressor 1 running with the control room temperature with the corresponding certain operating frequency of the difference of the design temperature of indoor temperature and remote controller.
When heating running, opposite with cooling operation, this air conditioner control valve 2 makes refrigerant flow and Returning heat-exchanger 4 from the order of heat exchanger 4 by compressor 1, heat exchanger 3, valve 5 shown in the solid line arrow.Like this, heat exchanger 3 play a role as condenser and to around emit heat.On the other hand, this air conditioner makes its rotation according to the control room internal fans such as setting air quantity of remote controller, thereby will be blown out to indoor through the warm braw that heat exchanger 3 has carried out heat exchange.And, to make compressor 1 running with the control room temperature with the corresponding certain operating frequency of the difference of the design temperature of indoor temperature and remote controller.
This air conditioner is in order to carry out the running of above-mentioned cooling and warming, as shown in Figure 9, has by drive circuit such as microcomputer, motor and other indoor set control part of forming (below, be called control part) 6 and off-premises station control part (below, be called control part) 7.Control part 6 is according to the indication control room internal fan drive motors that is sent by remote controller etc. the time, and control part 7 is passed on certain instruction, and control part 7 is according to this instruction control compressor 1.At this, so-called " certain instruction " is meant the corresponding operating frequency of difference with room temperature and setting value, the temperature of indoor heat converter 3 etc.In addition, air conditioner also has the indoor heat converter temperature sensor 8 of the temperature that detects heat exchanger 3, the outdoor heat converter temperature sensor 10 of the temperature of the inlet temperature sensor 9 of the inlet temperature of detection compressor 1, detection heat exchanger 4.
As mentioned above, freeze cycle is formed by connecting with refrigerant pipeline successively by compressor 1, condenser, valve 5, evaporimeter.When in such freeze cycle compressor 1 being carried out VFC, if the aperture of valve 5 is one regularly, when then the compressor revolution was low-speed running, the amount of refrigerant of the freeze cycle of flowing through was less.And in a large amount of cryogen flow of the Shi Zeyou that runs up through freeze cycle.This is because the flow passage resistance force of waterproof of freeze cycle is certain cause.
Like this, when making the amount of refrigerant of the freeze cycle of flowing through only depend on the compressor revolution, the amount of refrigerant of the evaporimeter of flowing through after a little while, refrigerant has promptly evaporated before not by evaporimeter and has been over.Therefore, vaporized refrigerant is risen by the overheated evaporator outlet temperature that makes in evaporimeter, thereby the heat exchanger effectiveness of evaporimeter reduces.In addition, when the amount of refrigerant of the evaporimeter of flowing through for a long time, the refrigerant in the evaporimeter can not evaporate fully.Therefore, have the refrigerant former state to discharge from evaporator outlet, this refrigerant is sucked by compressor 1 and causes and return the liquid phenomenon, and this often becomes the reason of compressor 1 damage.
In order to solve aforesaid problem, with frequency conversion etc. compressor 1 is being carried out in the freeze cycle of speed Control, use can control valve 5 apertures electric expansion valve.The feasible amount of refrigerant by evaporimeter of controllable expansion valve aperture often keeps optimised quantity whereby.
The prior art of control expansion valve opening for example is documented in the Japanese kokai publication hei 10-267430 communique.That is, adopted the control method that is called " crossing thermal control " of control expansion valve opening, the inlet temperature of this method instrumentation compressor 1 and the temperature of evaporimeter also make its difference (S-H) keep certain.Because the suction inlet of compressor 1 is connected to the outlet of evaporimeter with refrigerant tube, thereby if amount of refrigerant is suitable, the refrigerant temperature of the suction inlet of compressor 1 (inlet temperature) is then high slightly than the refrigerant temperature that evaporimeter is discharged.Above-mentioned control method has been utilized this fact exactly.
Yet, adopt this control method, owing between the variation of refrigerant flow and the variation of temperature measured, certainly lead to time delay, thereby cause for the controls such as rapid variation of indoor temperature and can not follow the trail of.Therefore, as shown in figure 10, often cause that expansion valve opening fluctuates up and down with respect to desired value to strengthen the phenomenon be known as " vibration ".When causing such oscillatory occurences,, cause indoor environment to worsen owing to can not stably carry out freeze cycle.
Therefore, in order to suppress this oscillatory occurences various methodologies has been proposed.For example, in the Japanese kokai publication hei 10-267430 communique following method has been proposed.At first, in an official hour interval, monitor (S-H).Then, (S-H) being measured the above number of times of first setting value that reaches higher than goal-setting value counts with the number of times that reaches than below the second low setting value of goal-setting value.And then, the maximum and the minimum of a value of the aperture of the expansion valve of detection central monitoring position.And, reaching setting when above at this counting, the aperture of expansion valve makes it be fixed on mean value between maximum and the minimum of a value in the control at certain time intervals.
Adopt such prior art constructions, use to be subjected to the inlet temperature of the bigger compressor that influences 1 and to utilize closed-loop control to control expansion valve than expansion valve opening.Therefore, on principle being impossible non-oscillating; Though produce effect aspect the extreme vibration convergence making, the vibration that produces to a certain degree then can not prevent.In addition, expansion valve opening will reach stable optimum value to be needed for a long time, and freeze cycle plays pendulum unavoidably in during this period of time.Perhaps exist and to carry out complicated problems such as control processing.
Summary of the invention
Purpose of the present invention solves above these problems with regard to being, a kind of air conditioner and control method thereof are provided, and it does not carry out FEEDBACK CONTROL and can determine the aperture of valve reliably, thereby it is stable that freeze cycle is realized.
Air conditioner of the present invention is installed in the temperature sensor of evaporimeter the mid portion of evaporimeter or leans on suction inlet one side by comparison.And, in electronic expansion valve controls, use the output of this sensor and the revolution of compressor, the best valve opening the when heat exchanger effectiveness that calculates evaporimeter according to certain computing formula reaches maximum is also controlled this electronic valve.
Description of drawings
Fig. 1 is the brief configuration figure of freeze cycle of the air conditioner of expression embodiments of the invention 1.
Fig. 2 is the control system block diagram of the air conditioner of embodiments of the invention 1.
Fig. 3 is that the benchmark expansion valve opening of air conditioner of expression embodiments of the invention 1 is to the performance plot of compressor revolution.
Fig. 4 is that the benchmark evaporator temperature of air conditioner of expression embodiments of the invention 1 is to the performance plot of compressor revolution.
Fig. 5 be expression embodiments of the invention 1 air conditioner the ratio evaporator temperature and than the performance plot of the relation of expansion valve opening.
Fig. 6 is that the variation of evaporimeter medium temperature of air conditioner of expression embodiments of the invention 1 is to the performance plot of the variation of expansion valve opening.
Fig. 7 is the air conditioner of embodiments of the invention 2 and the block diagram of control system.
Fig. 8 is the concise and to the point pie graph of the freeze cycle of the existing air conditioner of expression.
Fig. 9 is existing air conditioner and control system block diagram.
Figure 10 is the performance plot of the oscillation action of the existing air conditioner of explanation.
The specific embodiment
Below, with reference to the description of drawings embodiments of the invention.In addition, be marked with identical symbol, to omit its detailed description for identical part.
Embodiment 1
Fig. 1 is the brief configuration figure of freeze cycle of the air conditioner of the expression embodiment of the invention 1.This air conditioner has compressor 21, cross valve 22, indoor heat converter (below, be called heat exchanger) 23, outdoor heat converter (below, be called heat exchanger) 24, electric expansion valve (below, be called valve) 25.They are connected and the formation freeze cycle with refrigerant pipeline 20.During refrigeration, heat exchanger 23 plays a role as condenser as evaporimeter, heat exchanger 24; When heating, heat exchanger 24 plays a role as condenser as evaporimeter, heat exchanger 23.
Fig. 2 is the schematic block diagram of control system of the air conditioner of the embodiment of the invention 1.This air conditioner is for carrying out cooling and warming running, has by the drive circuit of microcomputer, motor etc., the indoor set control section that other is formed (below, be called control part) 26 and off-premises station control section (below, be called control part) 71.Control part 26 is according to (not shown) such as indication control room internal fan drive motors that sent by remote controller the time, and the indication of regulation is transferred to control part 71.In addition, air conditioner also have the temperature that detects heat exchanger 23 indoor heat exchange temperature sensor (below, be called sensor) 28, detect the inlet temperature of compressor 21 the inlet temperature sensor (below, be called sensor) 29, detect the outdoor heat exchange temperature sensor (below, be called sensor) 30 of the temperature of heat exchanger 24.Each temperature sensor 28,29,30 is made of thermistor equitemperature detecting element.
Control part 71 uses the indoor heat converter temperature of passing on by control part 26, outdoor heat converter temperature from sensor 30 transmissions, from the compressor inlet temperature that sensor 29 sends, air conditioner is controlled from the data such as compressor revolution that compressor rotation detector (not shown) sends.In addition, in the present embodiment, sensor 28 and sensor 30 respectively driving fit be installed in heat exchanger 23,24 central part, be mid portion.This is the influence in order to make it can detect the mean temperature of heat exchanger 23,24 and be difficult to be subjected to expansion valve opening.Also can be like this, when sensor 28 and sensor 30 play a role as evaporimeter at heat exchanger 23,24, set in advance between the mid portion and suction inlet of evaporimeter.
Calculating unit 71A constitutes the part of control part 71.The aperture of the expansion valve when calculating unit 71A calculates refrigerant flow at that time evaporimeter and reaches the best is in order to control valve 25.In order to carry out this control, calculating unit 71A use the compressor revolution and the heat exchanger that plays a role as evaporimeter in detected heat exchanger temperature (evaporator temperature).So-called " heat exchanger that plays a role as evaporimeter " is heat exchanger 23 when cooling operation, is heat exchanger 24 when heating running.
Below, illustrate that calculating unit 71A calculates the method that evaporator effectiveness reaches the expansion valve opening of maximum.Fig. 3 represents that with respect to the compressor revolution evaporator effectiveness when turning round air conditioner under the standard performance experimental condition reaches the aperture (benchmark expansion valve opening) of the expansion valve of maximum.And among Fig. 3, be to be used for the expansion valve opening that the umber of pulse of the stepper motor of driver's valve 25 is represented with supply.That is, establish valve 25 and when certain specific aperture, be " O ", counting in order to make valve 25 reach certain aperture umber of pulse necessary, that supply with stepper motor from here on.So, when representing the concerning of known compressor revolution and benchmark expansion valve opening with empirical equation then as shown in the formula:
Phz=K11+K12 * N-K13 * N
2Formula (1)
In the formula: Phz is benchmark expansion valve opening (umber of pulse),
N be the compressor revolution (revolutions per second),
K11, K12, K13 is the constant that specification determined by air conditioner.
Inventors etc. pass through the experiment of the cooling operation that carried out, try to achieve:
K11=59,K12=3.147,K13=0.01241。
Fig. 4 is the performance plot with respect to the benchmark evaporator temperature of compressor revolution of expression air conditioner.Fig. 4 represents is revolution with respect to air conditioner, the evaporator temperature (benchmark evaporator temperature) when making the efficient of evaporimeter reach maximum with standard test conditions running air conditioner and the aperture of adjusting expansion valve.Like this, when representing the concerning of known compressor revolution and benchmark evaporator temperature with empirical equation then as shown in the formula:
Tec=K21+K22/N-K23 * N formula (2)
In the formula: Tec be the benchmark evaporator temperature (℃)
K21, K22, K23 are the constant that specification determined by air conditioner.
Inventors etc. pass through the experiment of the cooling operation that carried out, try to achieve:
K21=13.72,K22=157.8,K23=0.04217。
Fig. 5 is the ratio evaporator temperature of expression air conditioner and than the performance plot of the relation of expansion valve opening.The performance plot of Fig. 5 is following tries to achieve.With certain compressor revolution running air conditioner, when making evaporator effectiveness reach maximum, the aperture of adjustment expansion valve measures evaporator temperature.To remove value that expansion valve opening at this time obtains as than expansion valve opening P with benchmark expansion valve opening Phz.In addition, will remove value that evaporator temperature obtains as than evaporator temperature tec with benchmark evaporator temperature Tec.Instrumentation these than expansion valve opening P with than evaporator temperature tec, repeat above instrumentation and just try to achieve while change environmental condition than evaporator temperature tec and relation than expansion valve switch P.Like this, when represent with empirical equation to have tried to achieve than evaporator temperature tec with than the concerning of expansion valve opening the time then as shown in the formula:
P=K31+K32 * tec+K33 * tec
2Formula (3)
Wherein: P is than expansion valve opening (umber of pulse),
Tec be than evaporator temperature (℃),
K31, K32, K33 is the constant that specification determined by air-conditioner.
Inventors etc. pass through the experiment of the cooling operation that carried out, try to achieve:
K31=0.7445,K32=0.1424,K33=0.106。
Fig. 6 is the performance plot of expression with respect to the variation of the variation evaporimeter medium temperature of expansion valve opening, is the air conditioner that turns round under certain certain operating condition, measures the result that evaporator temperature obtains while change the aperture of expansion valve.Judge also have only change slightly even change the temperature of the aperture evaporimeter of expansion valve according to Fig. 6.
Device has microcomputer and the memory that stores the program of operational formula (1), (2), (3) among the calculating unit 71A.Then, calculate benchmark expansion valve opening Phz with formula (1), calculate benchmark evaporator temperature Tec with formula (2) by detected compressor revolution N.And then, calculating unit 71A with formula (3) by remove calculating than expansion valve opening P that detected evaporator temperature obtains with benchmark evaporator temperature Tec than evaporator temperature tec.Thereafter, by asking product, obtain in compressor revolution at that time, the optimum expansion valve opening under the evaporator temperature than expansion valve opening P and benchmark expansion valve opening Phz.By using this optimum expansion valve opening to come control valve 25, as the input information that is used to control, then can not use to expansion valve opening have big influence to usually realize control.Therefore, can under the situation that does not cause vibration, stably carry out the freeze cycle running.
In the air conditioner of present embodiment, thereby the computing formula of having been programmed in advance by the microcomputer computing that is built among the calculating unit 71A calculates the optimum expansion valve opening.But, in advance result of calculation is stored among the memory unit 71C as data, can obtain same effect by accessing to control also again with detected revolution and the corresponding data of evaporator temperature.If control valve 25 like this, then can carry out the freeze cycle running rapidly and stably.
Though the constant of each formula has been described with cooling operation in the above-mentioned explanation, when heating running, then these constants must be replaced into different values to control.
Embodiment 2
Fig. 7 is the schematic block diagram of the employed control device of control method of the air conditioner of embodiments of the invention 2.Be in outdoor control part (below, be called control part) 72, to have packed into to calculate from time that change compressor revolution begins and the 71B of timing portion that compares with setting-up time.Structure in addition is identical with embodiment 1.
The 71B of timing portion plays timer at control part 72 and begins counting when changing the compressor revolution, judge whether to surpass the pre-set time.If revolution does not change, then control part 72 carries out the running of freeze cycle by the benchmark expansion valve opening of formula (1) calculating of embodiment 1.And if judge the time that process is set by the 71B of timing portion, then control part 72 carries out the running of freeze cycle with regard to the optimum expansion valve opening of calculating by formula (1), (2), (3) of being used embodiment 1 by calculating unit 71A.Adopt such structure,, also can under the situation of calculating optimum expansion valve opening after the approximate running, carry out the calculating of reliable umber of pulse in advance even have at the compressor revolution under the situation of very big change.
As mentioned above, adopt the present invention, affected less and compressor by expansion valve opening by detection The temperature that revolution, environment temperature etc. are compared the mid portion of the bigger evaporimeter of change expands with decision Valve opening. Therefore, do not need complicated FEEDBACK CONTROL then can stably control freeze cycle. In addition, Because in calculating, make expansion valve opening and evaporimeter mid portion temperature zero dimension, thereby, namely Make in making the process of computing formula and make with specific compressor revolution, but also can use In other revolution. Therefore, the experiment man-hour in the time of can saving exploitation.
Claims (4)
1. air conditioner, it is characterized in that, have: the compressor of power variable, condenser, electric expansion valve, evaporimeter, be arranged on the temperature sensor of temperature that is used to detect above-mentioned evaporimeter at any place between the suction inlet of the pars intermedia of the pars intermedia of above-mentioned evaporimeter or above-mentioned evaporimeter and above-mentioned evaporimeter, use the output of said temperature sensor and the revolution of above-mentioned compressor, the aperture of controlling above-mentioned electric expansion valve is to best aperture, thereby make the heat exchanger effectiveness of the above-mentioned evaporimeter when the temperature of said temperature sensor output reach maximum control part.
2. air conditioner according to claim 1 is characterized in that, also has the storage part that stores above-mentioned best aperture, and above-mentioned control part uses the above-mentioned best aperture that is stored in the above-mentioned storage part to control the aperture of above-mentioned electric expansion valve.
3. the control method of an air conditioner, this air conditioner has: the compressor of power variable, condenser, electric expansion valve, evaporimeter, it is characterized in that having following steps: the step of temperature that 1. detects the above-mentioned evaporimeter at any place between the suction inlet of the pars intermedia of the pars intermedia of above-mentioned evaporimeter or above-mentioned evaporimeter and above-mentioned evaporimeter; 2. detect the step of the revolution of above-mentioned compressor; 3. for the said temperature of above-mentioned evaporimeter and the above-mentioned revolution of above-mentioned compressor, make the heat exchanger effectiveness of the detected above-mentioned evaporimeter when the said temperature of above-mentioned evaporimeter reach maximum, the aperture of above-mentioned electric expansion valve is controlled to the step of best aperture.
4. the control method of air conditioner according to claim 3 is characterized in that: also have: store the step of above-mentioned best aperture, use the above-mentioned above-mentioned best aperture that has stored to control above-mentioned electronic expansion valve opening.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002323446A JP2004156844A (en) | 2002-11-07 | 2002-11-07 | Air conditioner and its control method |
JP2002323446 | 2002-11-07 |
Publications (2)
Publication Number | Publication Date |
---|---|
CN1499148A CN1499148A (en) | 2004-05-26 |
CN1268882C true CN1268882C (en) | 2006-08-09 |
Family
ID=32803307
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN 200310103272 Expired - Fee Related CN1268882C (en) | 2002-11-07 | 2003-11-04 | Air conditioner and its control method |
Country Status (2)
Country | Link |
---|---|
JP (1) | JP2004156844A (en) |
CN (1) | CN1268882C (en) |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008190840A (en) * | 2007-02-08 | 2008-08-21 | Matsushita Electric Ind Co Ltd | Heat pump type water heater |
CN101446463B (en) * | 2007-11-27 | 2011-07-20 | 珠海格力电器股份有限公司 | Control method of electronic expansion valve, and self-adaptive control method and device of heat pump device |
CN102003773A (en) * | 2010-11-25 | 2011-04-06 | 佛山市中格威电子有限公司 | Shunt compensation control system of inverter-driven multi-split air conditioner |
CN102252475B (en) * | 2011-05-06 | 2012-10-10 | 宁波奥克斯电气有限公司 | Method for adjusting electronic expansion valve of turned-off indoor unit during heating of VRV (Varied Refrigerant Volume) air-conditioning system |
JP5370560B2 (en) * | 2011-09-30 | 2013-12-18 | ダイキン工業株式会社 | Refrigerant cycle system |
CN105627524B (en) * | 2016-03-14 | 2018-06-01 | 广东美的制冷设备有限公司 | Air conditioner anti-freeze control method and air conditioner |
CN111483286B (en) * | 2019-01-25 | 2022-10-18 | 宇通客车股份有限公司 | Method and device for calculating opening degree of regulating valve of vehicle air conditioning system |
JP2021134940A (en) * | 2020-02-21 | 2021-09-13 | パナソニックIpマネジメント株式会社 | Refrigerating device |
CN111397252B (en) * | 2020-02-26 | 2022-03-25 | 浙江中广电器股份有限公司 | Control method and processor beneficial to running of water heater in high-temperature environment and water heater |
CN115451621B (en) * | 2021-06-09 | 2024-08-09 | 青岛海特生物医疗有限公司 | Method and device for adjusting frequency of compressor and compressor |
-
2002
- 2002-11-07 JP JP2002323446A patent/JP2004156844A/en active Pending
-
2003
- 2003-11-04 CN CN 200310103272 patent/CN1268882C/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JP2004156844A (en) | 2004-06-03 |
CN1499148A (en) | 2004-05-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN1229612C (en) | Air conditioner and its control method | |
CN1220004C (en) | Control system of degree of superheat of air conditioner and ocntrol method thereof | |
CN1268882C (en) | Air conditioner and its control method | |
CN1283964C (en) | Air conditioner | |
CN105202695A (en) | Dust removal control method and device for heat exchanger of outdoor unit of air conditioner | |
WO2017070093A1 (en) | Hydrophobic heat exchangers | |
CN1255654C (en) | Method for self-adaptive optimizing controlling cold water system of central air conditioner and its apparatus | |
KR20120010252A (en) | Control system for operating condenser fans cross reference to related applications | |
CN1165940A (en) | Defrosting control method for air conditioner | |
JP2001010332A (en) | Electrically driven type compression cooling system having supercritical process | |
WO2015064172A1 (en) | Air conditioner | |
RU2551708C1 (en) | Method to control speed of variable-speed compressor | |
CN1148544C (en) | Outdoor fan control sysem of air conditioner and control method thereof | |
WO2014170982A1 (en) | Heat pump device and air-conditioning system | |
CN111306732B (en) | Control method of drainage water pump of water receiving disc of air conditioner and air conditioner | |
CN1156810A (en) | Air-conditioner | |
CN105241171B (en) | Using the controlling method for refrigerator and control system of linear compressor | |
CN1807889A (en) | Helical-lobe compressor for refrigerating plant | |
CN110953684B (en) | Control method of air conditioner cooling system and air conditioner | |
CN113701326A (en) | Outdoor fan speed regulation control device and system for heat pump | |
CN1892132A (en) | Air-conditioner and control method | |
CN113915900B (en) | Refrigerator and constant-temperature refrigeration method thereof | |
BRPI0318601B1 (en) | linear compressor drive control apparatus and method | |
CN1888672A (en) | Air conditioner indoor heat exchanger freezing preventing controlling method | |
JP2003050066A (en) | Controller for air conditioner |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C06 | Publication | ||
PB01 | Publication | ||
C10 | Entry into substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
C14 | Grant of patent or utility model | ||
GR01 | Patent grant | ||
C17 | Cessation of patent right | ||
CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20060809 Termination date: 20111104 |